Gas generator

ABSTRACT

A LIGHTWEIGHT MULTI-PHASE GAS GENERATOR HAVING A SINGLE PRESSURE CHAMBER DEFINING TUBE CONTAINING A ROCKET PROPELLANT GRAIN. A BOOSTER GRAIN IS CONCENTRICALLY INTERGRAL WITH THE PROPELLANT GRAIN REARWARD END AND HAS BONDED THERETO AN END PORTION OF A FRANGIBLE AND FLEXIBLE BOOT THAT LINES THE CENTRAL LONGITUDIANL PASSAGE OF THE PROPELLANT GRAIN. ALIGNED APERTURES IN THE BOOSDTER GRAIN AND BOOT END PORTION PLACE THE IGNITER IN FLUID COMMUNICATION WITH THE BOOT INTERIOR, SUCH THAT UPON BOOSTER GRAIN IGNITION DEVELOPED PRESSURE GAS WILL EXPAND THE BOOT WALL OUTWARDLY TO PROTECT THE INNER SURFACE OF THE ROCKET PROPELLANT GRAIN FORM PREMATURE IGNITION BEFORE SUBSTANTIAL COMPLETION OF THE INITIAL BOOSTER PHASE.

J. B. MCCORMICK GAS GENERATOR Filed June 8, 1970 INVENTOR,

JOSEPH B. MCCORMICK ATTORNEYSZ United States Patent O 3,609,977 GAS GENERATOR Joseph B. McCormick, Willingboro, NJ., assignor to the United States of America as represented by the Secretary of the Army Filed June 8, 1970, Ser. No. 44,488 Int. Cl. F02k 9/06 U.S. Cl. 60-245 3 Claims ABSTRACT F THE DISCLOSURE A lightweight multi-phase gas generator having a single pressure chamber dening tube containing a rocket propellant grain. A booster grain is concentrically integral with the propellant grain rearward end and has bonded thereto an end portion of a frangible and flexible boot that lines the central longitudinal passage of the propellant grain. Aligned apertures in the booster grain and boot end portion place the igniter in fluid communication with the boot interior, such that upon booster grain ignition developed pressure gas will expand the boot wall outwardly to protect the inner surface of the rocket propellant grain from premature ignition before substantial completion of the initial booster phase.

The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to gas generators and, more particularly to a multi-phase gas generating system.

It is an object of the invention to provide a multi-phase gas generating system which is lightweight and requires but a single igniter. Another object of the invention is to provide such a gas generating system or arrangement wherein the need is eliminated for a phase separating booster tube or supporting bulkhead normally associated' with catapult grains, as well as the need for an inhibitor coating on the rocket grain inner surface.

These and other objects, features and advantages will become mo-re apparent from the following description and accompanying drawing in which the sole figure is a sectional view embodying the principles of the invention.

The lightweight multi-phase gas generating system or rocket catapult has a single pressure chamber deiined by a suitable tubular member 10. The rearward portion of tube has an appropriately arranged igniter 11 that upon ignition will in turn ignite the booster grain 12 that is integral with the rearward portion of the rocket propellant grain 13. The booster grain is appropriately secured within the longitudinal or axial passage 14 of the propellant grain such that it is positioned concentrically in the propellant grain rearward end.

A flexible and frangible boot member 15 has its rearward end portion 16 bonded to the forward surface 17 of the booster grain 12. The boot rearward end 16 has a plurality of openings 18 that are in longitudinal alignment ice with corresponding longitudinal passages 19 which extend through the booster grain such that generated pressure gas can reach the interior of the boot 15. The boot forward end (not shown) is supported by the forward end (not shown) of tube 10 or other suitable support surface, and during the initial catapult or booster ignition phase the developed pressure gas will assure outward expansion of the boot sidewall against the rocket propellant grain 13 to protect its inner surface 14 against premature ignition. At a predetermined time substantially near completion of the booster grain burning, the flame front would have progressed beyond the bonded joint 20 between the forward surface 17 of the booster grain 12 and the rearward end portion of the boot 15. The hot gas pressure will now be able to ignite the rocket propellant grain inner surface 14 causing the boot material 15 to break up or collapse and be expelled from the rearmost positioned rocket nozzle (not shown) which would be predeterminedly located aft of the igniter 11. Thus, the uninhibited rocket propellant grain can then burn without obstruction to provide the desired rocket ignition phase in the predetermined controlled manner.

yI wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

I claim:

1. In a multi-phase gas generator system having a single pressure chamber defining tube,

a propellant grain located within said tube and having an axial passage therethrough,

a booster grain integral with said propellant grain at a rearward end thereof and having longitudinal passage means extending therethrough, and

a frangible and flexible boot substantially lining said propellant grain axial passage and having an end portion bonded to said booster grain.

2. The arrangement in accordance with claim 1 wherein said boot end portion includes aperture means longitudinally aligned with said booster grain passage means.

3. The arrangement of claim 1 wherein said booster grain is concentrically positioned within said propellant grain rearward end.

References Cited UNITED STATES PATENTS 2,799,987 7/1957 Chandler 60-245 3,115,008 12/1963 Cohen et al. 60-245 3,158,061 11/1964 Lager 60-250 3,430,445 3/ 1969 Smith 60-245 y 3,564,845 2/1971 Friedman et al` 60-250 MARK M. NEWMAN, Primary Examiner W. E. OLSEN, Assistant Examiner U.S. Cl. X.R. 

